JP2007163216A - Radiation detection device and radiation imaging system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly-reliable radiation detection device capable of securing a uniform light quantity in a photoelectric conversion element array domain of a sensor panel, concerning the radiation detection device having a light irradiation function. <P>SOLUTION: This radiation detection device has a scintillator panel 1 for converting a radiation into light, a photoelectric conversion element array 2 wherein a plurality of photoelectric conversion elements for converting light into an electric signal are arranged in a two-dimensional array shape on a substrate 4, and the sensor panel 5 equipped with a wiring pad part 3 on the peripheral part. A light guide plate 6 smaller than the sensor panel 5 and approximately equal to the photoelectric conversion element array domain A1-A2 is installed, and a light generator 7 and a support substrate 8 are installed on a non-sensitive domain A2-B1 on its outside. The photoelectric conversion element array domain A1-A2 is irradiated with light from the light generator 7 through the light guide plate 6 as uniform light. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radiation detection apparatus and a radiation imaging system used for medical diagnostic equipment, non-destructive inspection equipment, and the like, and more particularly to a radiation detection apparatus and radiation imaging system used for X-ray photography and the like. In the present specification, the description will be made assuming that the category of radiation includes electromagnetic waves such as X-rays and γ-rays.

  Conventionally, an X-ray film system having a fluorescent screen having an X-ray phosphor layer provided therein and a double-side coating agent has been generally used for X-ray photography. However, recently, the image characteristics of a digital radiation detection apparatus having an X-ray phosphor layer and a two-dimensional photodetector are good, and since the data is digital data, the data is obtained by taking it into a networked computer system. Since there is an advantage that sharing of the digital radiation detection device has been achieved, research and development has been actively conducted on digital radiation detection devices, and various patent applications have been filed.

  Among these digital radiation detection apparatuses, as disclosed in Patent Document 1, as a highly sensitive and sharp apparatus, a plurality of photoelectric conversion elements and electric elements such as TFTs (Thin Film Transistors) are two-dimensionally arranged. 2. Description of the Related Art A radiation detection apparatus is known in which a phosphor layer for converting radiation into light that can be detected by a photoelectric conversion element is formed on a photodetector including a photoelectric conversion element portion.

  As described above, in a radiation detection apparatus using a scintillator (wavelength converter) such as a phosphor that converts radiation into visible light and a sensor panel having a plurality of photoelectric conversion elements, dark current is generated in still image shooting or the like. May occur. This is due to past radiation irradiation history, bias application history, residual charge due to transfer residue remaining in the photoelectric conversion element, trap charge trapped in a defect in the photoelectric conversion element, and the like. In addition, in moving image shooting in which images are acquired a plurality of times, element characteristics change, which may adversely affect image characteristics. In particular, when a photoelectric conversion element having a non-single-crystal semiconductor layer such as amorphous silicon is used, the photoelectric conversion element has many defects, so that the influence of trapped charges trapped in the defects is large.

  As a countermeasure, a technique for improving the characteristics of the photoelectric conversion element by arranging a light source on the back side of the radiation detection apparatus and irradiating the photoelectric conversion element with light from the light source is known. This technique is also called optical reset, bias light irradiation, optical calibration, and the like. According to this, it is possible to forcibly generate a charge in the photoelectric conversion element by light irradiation and read it without using it as image information, or to generate a charge equivalent to the amount taken into the defect to fill the defect level.

  In this technique, a configuration in which a light guide plate (optical waveguide) used for a backlight of a liquid crystal display device is arranged between a sensor panel and a light source as an arrangement configuration of the light source is being studied.

  A conventional radiation detection apparatus provided with a light source that performs light irradiation as described above will be described below.

  FIG. 13 is a cross-sectional view (see Patent Document 2) showing a conventional radiation detection apparatus, and shows the arrangement of the X-ray flat panel detector 110 and the light generator 120. The X-ray flat panel detector includes a surface electrode 111, an X-ray conversion layer 112, and a detection array layer 113. The light generator 120 includes a light reflection film 121, a light guide plate 122, a light source body 123, and a light diffusion film 124.

In this configuration, the light generator 120 causes the light from the light source body 123 to enter the X-ray flat panel detector 110 to irradiate the photoelectric conversion element described above. Thereby, it is possible to improve the transmission efficiency of signal charge of a signal having a particularly low value. The light generator 120 is formed in such a size that the light guide plate 122 for light irradiation covers at least the light receiving surface.
JP 2000-284053 A JP 2004-033659 A

  However, in the radiation detection apparatus of the above-described conventional example, since the diffusion plate is disposed up to the light source main body, the photoelectric conversion element array close to the light source main body is not only transmitted light from a normal light guide plate but also from the light source main body. The light irradiated through the light diffusion film reaches additionally. For this reason, the photoelectric conversion element array close to the light source body has an excessive amount of light for light irradiation as compared with other photoelectric conversion element arrays.

  Although not shown, an external output terminal after photoelectric conversion is necessary, and when the external output terminal is installed outside the X-ray flat panel detector, the external output terminal part and the light source body part are used for radiography. It becomes a dead area and the radiation imaging range is limited. It is necessary to make this dead area as small as possible.

  Furthermore, since the light source body is only sandwiched between the light reflecting film and the light diffusing film, there is a risk that the light source body may be damaged when an external force is applied.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a highly reliable radiation detection apparatus that secures a uniform amount of light for light irradiation in a photoelectric conversion element array region of a sensor panel in a radiation detection apparatus having a light irradiation function.

  In order to achieve the above object, a radiation detection apparatus according to the present invention includes a scintillator that converts incident radiation into first light in a wavelength band that can be sensed by a photoelectric conversion element, and converts the first light into an electrical signal. In a radiation detection apparatus having a photoelectric conversion element array having an effective pixel region in which a plurality of photoelectric conversion elements are arranged in a two-dimensional array and a sensor panel having an electrode pad portion on the outer periphery thereof, the second light is emitted. And a light guide plate disposed on a surface of the sensor panel facing the scintillator and configured to guide and irradiate the second light to the photoelectric conversion element array side. The light guide plate is smaller than the sensor panel. Unlike the first light, the second light is light having no image information.

  In the present invention, the light guide plate has a size substantially equal to the effective pixel area of the photoelectric conversion element array, and irradiates the second light to a range substantially equal to the effective pixel area of the photoelectric conversion element array. It may be configured as follows. “Substantially equal” means substantially the same, in other words, the same or within a predetermined error tolerance.

  In the present invention, the light generator is disposed outside the light guide plate on a surface of the sensor panel facing the scintillator, and a support member that supports the sensor panel is disposed in a peripheral portion of the light generator. May be. The support member may be disposed on an outer peripheral portion of the sensor panel. The support member may have a function as an impact interference material. The support member may have a function as a light reflecting material.

  In the present invention, the light generator may partially have a light reflecting surface. The light guide plate may be provided with a light diffusion sheet on the surface on the sensor panel side. The light guide plate may be provided with a light reflecting sheet on a surface opposite to the sensor panel side. The photoelectric conversion element may include a non-single-crystal semiconductor layer disposed on an insulating substrate.

  A radiation imaging system according to the present invention includes any one of the radiation detection apparatuses described above. In the present invention, signal processing means for processing a signal from the radiation detection apparatus, recording means for recording a signal from the signal processing means, and display means for displaying a signal from the signal processing means The signal processing means may further comprise a transmission processing means for transmitting a signal and a radiation source for generating the radiation.

  According to the present invention, non-uniformity in the amount of light for light irradiation is corrected by installing a light guide plate smaller than the sensor panel. Further, the light guide plate, the light generator, and the support member can be installed within the size of the sensor panel. As a result, the insensitive area is minimized, the usable area of the sensor panel during radiography is expanded, and the support member can be installed, thereby increasing the mechanical strength of the light generator. Therefore, it is possible to obtain a radiation detection apparatus that has a wide range of use and is more stable and reliable.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present specification, radiation includes X-rays, γ-rays, or particle beams such as α-rays and β-rays. The scintillator (wavelength converter) converts incident radiation such as X-rays and γ-rays into light in a wavelength band that can be detected by the photoelectric conversion element.

  FIG. 1 is a cross-sectional view showing the radiation detection apparatus of the present embodiment. The radiation detection apparatus of the present embodiment is applied to an indirect conversion type device that converts radiation into light with a scintillator and converts the light into an electrical signal with a photoelectric conversion element.

  In FIG. 1, 1 is a scintillator panel, 2 is a photoelectric conversion element array, 3 is a wiring / electrode pad section, and 4 is a substrate. The scintillator panel 1, the photoelectric conversion element array 2, the wiring / electrode pad portion 3, and the substrate 4 constitute a sensor panel 5.

  Among these, the scintillator panel 1 is comprised by the scintillator (for example, fluorescent substance) which converts the X-ray which injects into a radiation detection apparatus into visible light. The scintillator panel 11 can be mounted either by a method in which carbon or a film in which a scintillator is laminated on the photoelectric conversion element array 2 is bonded, or by a method in which the scintillator is directly deposited on the photoelectric conversion element array 2. is there.

  The photoelectric conversion element array 2 has an effective pixel region in which a plurality of photoelectric conversion elements that convert light into electric signals are arranged in a two-dimensional array. For example, the photoelectric conversion element array 2 includes a TFT (Thin Film Transistor) element as a switching element connected to a drive wiring and a signal line, and a photoelectric conversion element connected to the TFT element. As this photoelectric conversion element and TFT element, those having a non-single crystal semiconductor layer such as amorphous silicon provided on an insulating substrate are used.

  In FIG. 1, the area between A1 and A2 is a photoelectric conversion element array area corresponding to the effective pixel area of the photoelectric conversion element array 2, and the area between A2 and B1 is a dead area from the end of the sensor panel 5 to the photoelectric conversion element array 2. It is.

  In the figure, 6 is a light guide plate and 7 is a light generator. The light guide plate 6 and the light generator 7 constitute a light irradiation unit 10 that performs light irradiation on the photoelectric conversion element array 2. The light guide plate 6 is smaller than the sensor panel 5 on the chassis 9 and has a size substantially equal to the photoelectric conversion element array region A1-A2.

  According to this, the light from the light generator 7 is irradiated through the light guide plate 6 into the photoelectric conversion element array A1-A2 region on the sensor panel 5 side. By this light irradiation, electric charges are forcibly generated in the respective photoelectric conversion elements in the photoelectric conversion element array 2 and read without using them as image information, or charges corresponding to the amount taken into the defects are generated, thereby generating defect levels. You can fill the rank. Thereby, the characteristic improvement of a photoelectric conversion element can be aimed at.

  Further, 8 is a support member for protecting the light generator 102 and increasing the mechanical strength of the outer peripheral portion, and 9 is a mounting chassis made of SUS (stainless steel) or the like. The support member 8 is formed at the same height as the light guide plate 6 and is installed outside the region of the photoelectric conversion element array 2. Further, the upper portion of the light generator 7 of the support member 8 has a light reflecting function in order to increase the light transmission efficiency from the light generator 102 to the light guide plate 6 in this embodiment. Above the support member 8, the light generator 7, and the light guide plate 6, the aforementioned sensor panel 5 is installed.

  The sensor panel 5, the light guide plate 6, the light generator 7, the support member 8, and the chassis 9 constitute the radiation detection apparatus of this embodiment. According to this radiation detection apparatus, by making the photoelectric conversion element array region A1-A2 and the light guide plate 6 have substantially the same size, a uniform amount of light can be obtained in the photoelectric conversion element array region A1-A2. Further, since the light generator 7 is installed in the area occupied by the sensor panel 5 (insensitive area A2-B1), the insensitive area is minimized and the usable area of the sensor panel 5 during radiography is expanded. Is possible. Further, since the support member 8 also serves as a mechanical protection part, it is possible to prevent the light generator 7 from being broken due to external pressure or impact. Therefore, according to the present embodiment, it is possible to obtain a radiation detection apparatus having high reliability and a wide range of imaging conditions.

  Next, the radiation detection apparatus of this embodiment will be described in detail using the following examples.

  First, a first embodiment of the present invention will be described with reference to FIGS.

  In the radiation detection apparatus according to the present embodiment, as shown in FIGS. 2 and 3, a light guide plate 6 that is smaller than the sensor panel 5 and has a size substantially equal to the photoelectric conversion element array region A1-A2 is installed on the chassis 9. Has been. The light guide plate 6 is preferably made of a resin material having high light propagation efficiency and high transparency, such as an acrylic resin. The size of the light guide plate 6 is more preferably about 1-2 mm larger than the photoelectric conversion element array region A1-A2 in consideration of the light diffusion component.

  Further, outside the light guide plate 6, the light generator 7 and the light guide plate 6 are at the same height on the outer periphery located in the insensitive regions B <b> 2-A <b> 1 and A <b> 2-B <b> 1 other than the photoelectric conversion element array region A <b> 1-A <b> 2. The processed support member 8 is installed. The light generator 7 is preferably a high output light source such as an LED (Light Emitting Diode), a cold cathode tube, or a semiconductor laser.

  The support member 8 can be integrated with the light generator 7 in advance. It is preferable that the upper surface of the light generator 7 of the support member 8 does not transmit light from the light generator 7 in order to increase the light transmission efficiency from the light generator 102 to the light guide plate 6. For this reason, in this embodiment, the support member 8 is made of the same SUS as the chassis 9 and has a function as a light reflecting material in combination with a function as an impact interference material. More preferably, the chassis 9 also serves as a light reflection function in order to increase the irradiation efficiency of the light irradiated from the light guide plate 6 to the photoelectric conversion element array region A1-A2. Since the width of the sensor panel bonding surface of the support member 8 is required to be about 5 to 15 mm for mounting, it is set within the range in this embodiment.

  In order to reduce the overall weight, the support members 8 are installed at four corners in the outer peripheral portion (a frame-shaped peripheral region having four sides) of the photoelectric conversion element array 2 on the substrate 4 as shown in FIG. 8 can be arranged. Or as shown in FIG. 5, it is also possible to arrange | position the supporting member 8 to each center part of four sides of an outer peripheral part. In addition, in order to increase the strength, it is also possible to employ a combination of the arrangement of these four corners and the central portion. Further, in order to further increase the strength, as shown in FIG. 6, support members 8 are arranged in the entire left and right sides constituting two sides (the left side and the right side in the drawing) of the four sides of the outer peripheral portion of the photoelectric conversion element array 2. It is possible. Alternatively, as shown in FIG. 7, the support member 8 can be installed in a frame shape on the entire outer periphery of the four sides.

  Therefore, according to the present embodiment, in the radiation detection apparatus having the light irradiation function, the photoelectric conversion element array area A1-A2 and the light guide plate 6 are made to have substantially the same size, so that the photoelectric conversion element array area A1-A2 A uniform amount of light can be obtained. Further, since the light generator 7 is installed in the area occupied by the sensor panel 5 (insensitive areas B2-A1, A2-B1), the insensitive area is minimized, and the usable area of the sensor panel at the time of radiography. Can be expanded. Furthermore, since the support member 8 also serves as a mechanical protection part, it is possible to prevent the light generator 7 from being damaged due to external pressure, impact, or the like. Therefore, a radiation detection apparatus having high reliability and a wide range of imaging conditions can be obtained.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  In the radiation detection apparatus according to the present embodiment, as shown in FIG. 8, in addition to the configuration of the first embodiment (see FIG. 3), between the light guide plate 6 and the substrate 4 positioned above the light guide plate 6, The light diffusing sheet 11 is arranged in a size substantially equal to the light guide plate 6. The support member 8 is processed and arranged at the same height as the height of the light guide plate 6 plus the thickness of the light diffusion sheet 11. Other configurations are the same as those of the first embodiment.

  The light diffusion sheet 11 is a sheet in which irregular irregularities are formed on the surface of a resin such as acrylic resin or polycarbonate. By installing this light diffusion sheet 11 on the upper part of the light guide plate 6, more uniform light for light irradiation can be obtained in the photoelectric conversion element array region A1-A2.

  As in the first embodiment, the installation location of the support member 8 is arranged at the four corners and the central portion in order to reduce the overall weight, as well as combinations of these arrangements to increase the strength, and further strength. In order to raise it, it is possible to install it in a frame shape in the entire left and right or the entire outer peripheral part.

  Therefore, according to the present embodiment, in addition to the same effect as the first embodiment, there is an advantage that more uniform light for light irradiation can be obtained by arranging the light diffusion sheet 11.

  Next, a third embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 9, in the radiation detection apparatus according to the present embodiment, in addition to the configuration of the second embodiment (see FIG. 8), between the light guide plate 6 and the chassis 9 positioned below it, A light reflecting sheet 12 is disposed. The light reflecting sheet 12 further extends to the insensitive areas B2-A1 and A2-B1 outside the light guide plate 6 and is arranged to the lower part of the light generator 7. Other configurations are the same as those of the first embodiment.

  The material of the light reflecting sheet 12 is preferably Al / PET (polyethylene terephthalate) or white PET. By installing the light reflecting sheet 12 below the light guide plate 6 and the light generator 7, it is possible to increase the transmission efficiency of light for light irradiation.

  Therefore, according to this embodiment, in addition to the same effects as those of the first embodiment, there is an advantage that the transmission efficiency of light for light irradiation can be increased by arranging the light reflecting sheet 12.

  Next, a fourth embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 10, in the radiation detection apparatus according to the present embodiment, in addition to the configuration of the first embodiment (see FIG. 3), light reflection is performed between the light guide plate 6 and the chassis 9 positioned below the light guide plate 6. A sheet 12 is disposed. The light reflecting sheet 12 further extends to the insensitive areas B2-A1 and A2-B1 outside the light guide plate 6 so as to cover the light generator 7 and the supporting member 8, and the outer side surface of the upper and lower portions and the supporting member 8. It is arranged in the part.

  The material of the light reflecting sheet 12 is preferably Al / PET or white PET as in the third embodiment. By installing the light reflecting sheet 12 below the light guide plate 6 and the light generator 7, it is possible to increase the transmission efficiency of light for light irradiation.

  Further, the upper portion of the light generator 7 covered with the light reflection sheet 12 is made the same as the height of the light guide plate 6 by omitting the support member 8. With this configuration, the usage amount of the support member 8 can be reduced, and the weight of the radiation detection apparatus can be reduced.

  Therefore, according to the present embodiment, in addition to the same effects as those of the first embodiment, the light reflection sheet 12 is arranged to increase the transmission efficiency of light for light irradiation, and the support member 8 on the upper portion of the light generator. There is an advantage that the weight of the radiation detection apparatus can be reduced by omitting.

  As in the first embodiment, the installation location of the support member 8 is arranged at the four corners and the central portion in order to reduce the overall weight, as well as combinations of these arrangements to increase the strength, and further strength. In order to raise it, it is possible to install it in a frame shape in the entire left and right or the entire outer peripheral part.

  Next, a fifth embodiment of the present invention will be described with reference to FIG.

  As shown in FIG. 11, the radiation detection apparatus according to the present embodiment adds a light diffusion sheet between the light guide plate 6 and the substrate 4 positioned above the light guide plate 6 in addition to the configuration of FIG. 10 of the fourth embodiment. 11 is arranged in the light guide plate 6 in substantially the same size.

  The light diffusion sheet 11 is a sheet in which irregular irregularities are formed on the surface of an acrylic resin or a polycarbonate resin, as in the second embodiment. By installing this light diffusion sheet 11 on the upper part of the light guide plate 6, more uniform light for light irradiation can be obtained in the photoelectric conversion element array region A1-A2.

  Therefore, according to the present embodiment, in addition to the same effects as those of the fourth embodiment, more uniform light irradiation light can be obtained by arranging the light diffusion sheet 11 on the light guide plate 6. There are advantages such as.

  In the sixth embodiment of the present invention, a radiation imaging system using the radiation detection apparatus according to the present invention will be described.

  FIG. 12 is a schematic diagram of this embodiment. In FIG. 12, the X-ray 6060 generated by the X-ray tube 6050 passes through the chest 6062 of the patient or subject 6061 and enters the radiation detection device 6040 having a scintillator mounted thereon. This incident X-ray includes information inside the body of the patient 6061. The scintillator emits light in response to the incidence of X-rays, and this is photoelectrically converted to obtain electrical information. This information is converted to digital. The image is processed by the image processor 6070 and can be observed on the display 6080 in the control room.

  Further, this information can be transferred to a remote place by a transmission means such as a telephone line 6090 and can be displayed on a display 6081 such as a doctor room in another place or stored in a storage means such as an optical disk, and a doctor at a remote place makes a diagnosis. It is also possible. It can also be recorded on the film 6110 by the film processor 6100.

  As described above, the present invention can be applied to medical X-ray sensors and the like, but is also effective when applied to other uses such as nondestructive inspection.

It is sectional drawing which shows the radiation detection apparatus which concerns on the 1st Embodiment of this invention. It is a top view which shows the radiation detection apparatus which concerns on 1st Embodiment. It is sectional drawing which shows the radiation detection apparatus which concerns on 1st Example of this invention. In a 1st Example, it is a top view which shows the installation position at the time of installing a supporting member in four corners. In a 1st Example, it is a top view which shows the installation position at the time of installing a supporting member in the center part. In a 1st Example, it is a top view which shows the installation position at the time of installing a supporting member in the left-right whole area. In a 1st Example, it is a top view which shows the installation position at the time of installing a supporting member in the frame shape in the whole outer peripheral part. It is sectional drawing which shows the radiation detection apparatus which concerns on the 2nd Example of this invention. It is sectional drawing which shows the radiation detection apparatus which concerns on the 3rd Example of this invention. It is sectional drawing which shows the radiation detection apparatus which concerns on the 4th Example of this invention. It is sectional drawing which shows the radiation detection apparatus which concerns on the 5th Example of this invention. It is a schematic diagram explaining the radiation imaging system using the radiation detection apparatus which concerns on the 6th Example of this invention. It is sectional drawing which shows the radiation detection apparatus of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Scintillator panel 2 Photoelectric conversion element array 3 Wiring and electrode pad part 4 Board | substrate 5 Sensor panel 6 Light guide plate 7 Light generator 8 Support member 9 Chassis 10 Light irradiation part 11 Light diffusion sheet 12 Light reflection sheet A1-A2 Photoelectric conversion element array Area A2-B1, B2-A1 Insensitive area

Claims (12)

A scintillator that converts incident radiation into first light in a wavelength band that can be sensed by the photoelectric conversion element, and a plurality of photoelectric conversion elements that convert the first light into an electric signal are arranged in a two-dimensional array. In a radiation detection apparatus having a photoelectric conversion element array having a pixel region and a sensor panel having an electrode pad portion on the outer periphery thereof,
A light generator for generating second light;
A light guide plate disposed on a surface of the sensor panel facing the scintillator and configured to guide and irradiate the second light to the photoelectric conversion element array side;
The radiation detection apparatus, wherein the light guide plate is smaller than the sensor panel.   The light guide plate has a size substantially equal to the effective pixel area of the photoelectric conversion element array, and is configured to guide and irradiate the second light to a range substantially equal to the effective pixel area of the photoelectric conversion element array. The radiation detection apparatus according to claim 1, wherein: The light generator is disposed outside the light guide plate on a surface of the sensor panel facing the scintillator,
The radiation detection apparatus according to claim 1, wherein a support member that supports the sensor panel is disposed in a peripheral portion of the light generator.   The radiation detection apparatus according to claim 1, wherein the support member is disposed on an outer peripheral portion of the sensor panel.   The radiation detection apparatus according to claim 1, wherein the support member has a function as an impact interference material.   The radiation detection apparatus according to claim 1, wherein the support member has a function as a light reflecting material.   The radiation detector according to claim 1, wherein the light generator has a light reflecting surface in part.   The radiation detection apparatus according to claim 1, wherein the light guide plate is provided with a light diffusion sheet on a surface on the sensor panel side.   The radiation detection apparatus according to claim 1, wherein the light guide plate is provided with a light reflection sheet on a surface opposite to the sensor panel.   The radiation detection apparatus according to claim 1, wherein the photoelectric conversion element includes a non-single-crystal semiconductor layer disposed on an insulating substrate.   A radiation imaging system comprising the radiation detection apparatus according to claim 1. Signal processing means for processing signals from the radiation detection device;
Recording means for recording a signal from the signal processing means;
Display means for displaying a signal from the signal processing means;
Transmission processing means for transmitting a signal from the signal processing means;
The radiation imaging system according to claim 11, further comprising a radiation source for generating the radiation.